The board resets itself at the last step of configuration startup, the moment GTS releases the IOs. Pin AC24 is tied to a board reset net, and unused IOBs default to pulldown at the frame level, so any bitstream that does not hold AC24 high kills the board right as it comes alive. Every tool reports this as DONE never going high, with the device wiped back to a pristine unconfigured state a few seconds later and nothing latched in BOOTSTS.
The fix for openXC7 users is one fasm line merged into your design fasm before fasm2frames:
LIOB33_SING_X0Y150.IOB_Y0.PULLTYPE.PULLUP